Apparatus to prevent reperfusion injury

ABSTRACT

Embodiments of a method and apparatus to prevent reperfusion injury. In one embodiment, blood flow proximal to a lesion is occluded. An infusion catheter is advanced to a region distal to the lesion and an anti-reperfusion injury drug is delivered. The lesion may then be treated with a dilating device to reintroduce blood flow to the region distal to the lesion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of pending U.S. patent applicationSer. No. 12/943,879 filed Nov. 10, 2010 issued as U.S. Pat. No.8,262,612 on Sep. 11, 2012 which is a divisional of U.S. patentapplication Ser. No. 11/026,598 filed Dec. 30, 2004, entitled “METHODAND APPARATUS TO PREVENT REPERFUSION INJURY” and issued as U.S. Pat. No.7,837,650 on Nov. 23, 2010.

TECHNICAL FIELD

The disclosure, in one embodiment, relates generally to the treatment ofheart related diseases, and more particularly, in one embodiment, to theprevention of reperfusion injury after a reperfusion procedure tore-establish blood flow to an ischemic region of an artery.

BACKGROUND

Cardiac ischemia is a situation in which the blood flow inside acoronary artery is restricted by a partial or complete blockage. As aresult, the heart cannot get enough oxygen-rich blood. The blockagewithin the coronary artery, which supplies the heart with oxygen-richblood, may be complete or partial. The most common cause of cardiacischemia is plaque build-up in the arteries due to the long-term effectsof coronary artery disease. This plaque build-up narrows the arteries tothe point where the amount of blood flowing through the arteries is notenough for the heart during times of physical exertion or emotionalstress.

Reperfusion by vascular intervention (e.g., angioplasty) has become thestandard therapy for coronary artery disease. A substantial subset ofpatients undertaken with timely revascularization, however, still failsto salvage myocardium especially under the condition of emergingischemia such as acute myocardial infarction and unstable angina. Inparticular, the cells distal to the blockage continue to degrade in aprocess known as “reperfusion injury”, even after blood flow isrestored. This unfavorable outcome stems from a discrepancy between anopen epicardial infarct-related artery and the absence of blood flow inthe damaged distal microvasculatures. In fact, studies have shown thateven after patients undergo successful revascularization by angioplastyand recover normal epicardial blood flow, a significant number of thesepatients failed to attain full recovery of microvascular flow. Thus,“myocardial perfusion” is the ultimate goal of reperfusion therapy,which reflects the distribution of blood at the capillary and tissuelevel.

Research projects have been proposed and undertaken to mitigatereperfusion injury after myocardial ischemia in large animal experimentsas well as clinical trials with using various biochemical compounds. Inanimal studies, the drugs are typically administered prior to inductionof ischemia in order to determine the overall benefits. In contrast,clinical settings do not allow the administration of the drug prior toischemia except for preventive therapy. Thus, the difference in thetiming of drug administration can be one of the major reasons why allthe previous clinical trials aiming to prevent reperfusion injury havefailed in spite of significant positive results in the animalexperiments.

In the clinical trials, systemic intra-venous administration has beencommonly used, and the method of intra-coronary infusion soon aftersuccessful revascularization has also been attempted. However, becausereperfusion injury is triggered by reperfusion therapy, and supposedlyignites a series of biological responses in a very immediate, rapidmanner, these systemic methods would be too late for the delivery of ananti-reperfusion injury agent to the ischemic lesion and are likely tomiss the critical time-window for the therapy. The systemic orintra-coronary administration of an anti-reperfusion injury agent willnot allow the agent to reach the ischemic area prior to reperfusion. Inorder to address reperfusion injury within the critical time window, alocal therapy system that enables drug delivery under the absence ofblood flow (ischemic condition) is needed.

SUMMARY

Embodiments of a method and apparatus to prevent reperfusion injury aredescribed. In one embodiment, blood flow proximal to a lesion isoccluded. An infusion catheter is advanced to a region distal to thelesion and an anti-reperfusion injury drug is delivered. The lesion maythen be treated with a dilating device to reintroduce blood flow to theregion distal to the lesion.

In one embodiment, a percutaneous device includes an elongated catheterhaving a proximal region and a distal region, within expandable membercoupled to the elongated catheter near the distal region. An infusioncatheter is disposed within a first lumen formed within the elongatedcatheter, and the infusion catheter is slideable within the first lumento extend a substantial length past the distal region of the elongatedcatheter. The infusion catheter may be adapted to release ananti-reperfusion drug.

Additional embodiments, features and advantages of the medical devicewill be apparent from the accompanying drawings, and from the detaileddescription that follows below.

SUMMARY

Embodiments of a method and apparatus to prevent reperfusion injury aredescribed. In one embodiment, blood flow proximal to a lesion isoccluded. An infusion catheter is advanced to a region distal to thelesion and an anti-reperfusion injury drug is delivered. The lesion maythen be treated with a dilating device to reintroduce blood flow to theregion distal to the lesion. In another embodiment, a medical deviceincludes an elongated catheter having a proximal region and a distalregion, an expandable member coupled to the elongated catheter near thedistal region and an infusion catheter disposed within a first lumenformed within the elongated catheter. The infusion catheter is slideablewithin the first lumen to extend a substantial length past the distalregion of the elongated catheter to release an anti-reperfusion drug.

There are numerous other embodiments which are described herein, andthese embodiments generally relate to the prevention of reperfusioninjury.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and notlimitation, in the figures of the accompanying drawings in which:

FIG. 1A illustrates a cross-sectional view of an arterial vessel whoseblood flow is impacted by the occlusive nature of a lesion.

FIG. 1B illustrates the expansion of a balloon catheter to occlude bloodflow near a region proximal to the lesion.

FIG. 1C illustrates a balloon-expandable stent deployed near lesion toreperfuse the arterial vessel.

FIG. 2 is a block diagram that generally describes one embodiment of amethod to prevent reperfusion injury.

FIG. 3A is a cross-sectional, side view of one embodiment of a medicaldevice that may be used to prevent reperfusion injury.

FIG. 3B is a cross-sectional view of the device shown in FIG. 3A takenalong line A-A.

FIG. 3C is a cross-sectional view of the device shown in FIG. 3A takenalong line B-B.

FIG. 3D is a cross-sectional view of the device shown in FIG. 3A takenalong line C-C.

FIG. 3E is a cross-sectional view of the device shown in FIG. 3A takenalong line D-D.

FIG. 4A is a cross-sectional, side view of another embodiment of amedical device that may be used to prevent reperfusion injury.

FIG. 4B is a cross-sectional view of the device shown in FIG. 4A takenalong line A-A.

FIG. 4C is a cross-sectional view of the device shown in FIG. 4A takenalong line B-B.

FIG. 4D is a cross-sectional view of the device shown in FIG. 4A takenalong line C-C.

FIG. 4E is a cross-sectional view of the device shown in FIG. 4A takenalong line D-D.

FIG. 4F is a cross-sectional view of the device shown in FIG. 4A takenalong line E-E.

FIG. 5A illustrates a cross-sectional, side view of an expandable memberthat occludes blood flow near a region proximal to a lesion formedwithin an arterial vessel.

FIG. 5B illustrates a guidewire advanced to a region distal to a lesion.

FIG. 5C illustrates an anti-reperfusion injury drug released from aninfusion catheter.

FIG. 5D illustrates the expandable member of a device in a deflatedstate to allow for the removal of the device from the arterial lumen.

FIG. 5E illustrates a separate catheter device having an expandablestent disposed near a distal end advanced through arterial lumen andpositioned near the lesion.

FIG. 5F illustrates a seperate catheter device having an expanded stent.

FIG. 6 is a block diagram illustrating another method for the preventionof reperfusion injury.

FIG. 7A illustrates another cross-sectional, side view of an expandablemember occluding blood flow near a region proximal to a lesion formedwithin an arterial vessel.

FIG. 7B illustrates an infusion catheter advanced past the lesion alongthe guidewire.

FIG. 7C illustrates the deflation of the expandable member for theremoval of the device.

FIG. 8A illustrates another cross-sectional, side view of an expandablemember to occlude blood flow near a region proximal to a lesion formedwithin an arterial vessel.

FIG. 8B illustrates an anti-reperfusion injury drug released from theguidewire for absorption by the arterial wall of the ischemic region.

FIG. 8C illustrates the deflation of the expandable member for theremoval of the device.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forthsuch as examples of specific materials or components in order to providea thorough understanding of the present disclosure. It will be apparent,however, to one skilled in the art that these specific details need notbe employed to practice the disclosure. In other instances, well knowncomponents or methods have not been described in detail in order toavoid unnecessarily obscuring the present disclosure. Embodiments of amedical device discussed below are described with respect to thetreatment of cardiac ischemia caused by the blockage of blood flow fromlesions within an arterial vessel. It may be appreciated, however, thatother blood vessels or channels in the body may be treated, andembodiments of the medical device are not limited in their applicabilityto treat coronary arteries.

Embodiments of a medical device and methods for preventing reperfusioninjury are described. FIGS. 1A-1C and the block diagram 200 of FIG. 2,taken together, generally describe one embodiment of preventingreperfusion injury with a percutaneous drug delivery device. FIG. 1Aillustrates a cross-sectional view of an arterial vessel 100 whose bloodflow is impacted by the occlusive nature of lesion 103 (i.e., plaqueaccumulation). As shown, the relatively normal blood flow 104 near theregion proximal 101 to lesion 103 is significantly blocked near theregion distal 102 to lesion 103, producing very little blood flow 105downstream to lesion 103. The lack of oxygenated blood to distal region105 results in ischemic conditions (generically represented by reference106), potentially resulting in a myocardial infarction. One method tore-establish blood flow to distal region 102 may be the application of areperfusion procedure. In one embodiment, a dilatation device (e.g., aspart of an angioplasty procedure) may be used to treat lesion 103, suchas the application of a balloon catheter or a stent to lesion 103.

In one embodiment, the ischemic region 106 may be treated with a drug toprevent reperfusion injury. In particular, an anti-reperfusion injurydrug is allowed to be absorbed into the arterial walls of the ischemicregion prior to re-establish blood flow past lesion 103. In order tomaximize the effectiveness of the anti-reperfusion injury drug toischemic region 106, blood flow past lesion 103 is blocked. Thetreatment of ischemic region 106 with an anti-reperfusion injury drugfirst involves occluding blood flow near the region proximal 101 tolesion 103 (block 201). As illustrated in FIG. 1B, a balloon catheter110 (or other occlusive device) may be inflated (or otherwise radiallyexpanded) near the proximal region 101 to occlude blood flow 104.Balloon catheter 110 also includes an infusion catheter portion that isadvanced past lesion 103 to the distal region 103 (block 202). Theinfusion catheter is used to deliver an anti-reperfusion injury drug 112to the ischemic region 106 of arterial vessel 100 (block 203). Theinfusion catheter along with balloon catheter 110 is then retracted fromarterial vessel 100, allowing for lesion 103 to be treated with adilating device to re-establish blood flow to ischemic region 106 (block204). As illustrated in FIG. 1C, a balloon-expandable stent or aself-expanding stent may be deployed to lesion 103 to reperfuse arterialvessel 100 distal to lesion 103. For clarity, this embodiment, and otherembodiments presented herein, are described with respect to theprevention of reperfusion injury to arterial vessels. It may beappreciated however, that in other embodiments, other vessels in thebody (e.g., peripheral) impacted by lesions or other forms of blockagemay be treated for reperfusion injury with the apparatus and methodsdescribed herein.

FIGS. 3A-3E illustrate detailed views of one embodiment of a medicaldevice for the percutaneous delivery of an anti-reperfusion injury drugto an ischemic region (e.g., an arterial vessel region distal to anocclusive lesion). FIG. 3A is a cross-sectional, side view of themedical device 300 (e.g., a balloon catheter) that includes an elongatedcatheter body 301 with a proximal portion 320 and a distal portion 321.Proximal portion includes a first lumen 308 to receive infusion catheter309. Infusion catheter 309 includes at least one infusion port 303, andin one embodiment, may be a Y-adapter. The inner wall of infusioncatheter 309 forms a second lumen 304 to receive guidewire 305. Proximalportion 320 also includes an infusion port for infusion catheter 309.

Distal portion 321 of medical device 300 includes an expandable member306 coupled to elongated catheter body 301. In one embodiment,expandable member 306 may be an inflatable balloon. Inflatable balloonswith respect to catheters are known in the art; accordingly, a detaileddescription is not provided herein. Infusion catheter 309 extendsthrough expandable member 306 to expose a distal tip portion. Guidewire305 may also extend out past a distal tip portion of infusion catheter309. In an alternative embodiment, guidewire 305 may include pressureand/or flow transducers that to monitor the blood pressure, blood flow,blood velocity, vascular resistance and/or vascular conductance. Firstport 302 leads to first lumen 307 for the insertion of an inflationmedium for expandable member 306. Infusion port 303 leads to secondlumen 304 for the passage of a therapeutic drug (e.g., ananti-reperfusion injury drug) to be released from distal portion 321 ofinfusion catheter 309. Infusion catheter 309 is generally described torefer to any type of percutaneous catheter structure adapted for thedelivery of therapeutic agents into a body vessel. Device 300 is anexemplary embodiment of an over-the-wire (“OTW”) catheter in whichelongated catheter body 301 and/or infusion catheter 309 is tracked overguidewire 305. As such, guidewire 305 extends along an entire length ofdevice 300.

FIGS. 3B-3E illustrate various cross-sectional views of medical device300. FIG. 3B in particular, is a cross-sectional view of device 300taken along line A-A illustrating the body of infusion catheter 309forming second lumen 304 to receive guidewire 305 near proximal portion320. FIG. 3C is a cross-sectional view of device 300 taken along lineB-B illustrating elongated catheter body 301 forming first lumen 307 forthe passage of an inflation medium from port 302 to expandable member306. Catheter body 301 also forms a third lumen 310 to receive infusioncatheter 309 which contains guidewire 305 within second lumen 304. FIG.3D is a cross-sectional view of device 300 taken along line C-C (throughexpandable member 306) showing first lumen 307 formed by expandablemember 306, as well as infusion catheter 309 containing guidewire 305within second lumen 304. Lastly, FIG. 3E is a cross-sectional view ofdevice 300 taken along line D-D (near distal portion 321) of infusioncatheter 309 containing guidewire 305 within second lumen 304.

In one embodiment, one of the significant features of medical device 300is the mobility of infusion catheter 309 within elongated catheter body301. Guidewire 305 and infusion catheter 309 may move independently withrespect to each other, as well as to elongated catheter body 301. Thatis, infusion catheter 309 is slideable within third lumen 310 to extendbeyond a distal section of expandable member 306. As described ingreater detail below, this feature allows infusion catheter 309 totraverse toward a region distal to a lesion and deliver ananti-reperfusion injury drug to a portion of the arterial vessel, whilethe stationary expandable member 306 maintains blockage of blood flow inthe region proximal to the lesion. The application of ananti-reperfusion injury drug prior to reperfusion treatment of thelesion may be important because a period of time is allowed for the drugto infuse into the arterial wall and take effect. If blood flow werere-established about the same time as delivering the anti-reperfusioninjury drug, the drug may not effectively be absorbed by the arterialwall. In one embodiment, a diameter of infusion catheter 309 is sized tobe small enough to advance across an occlusive arterial lesion withoutcausing a large channel or reperfusion pathway from forming.

In one embodiment, a distal section of infusion catheter 309, which isto be positioned downstream of a lesion, has a profile that isrelatively small or smaller than the section of infusion catheter 309which is near or spans across the lesion. For example, infusion catheter309 may have a tapered diameter that gradually reduces in size near thedistal section.

FIGS. 4A-4F illustrate detailed views of another embodiment of a medicaldevice 400 for the delivery of an anti-reperfusion injury drug to anarterial vessel. Device 400 includes similar structural elements asdevice 300 described above with respect to FIG. 3A including anelongated catheter body 401, a proximal portion 420 with a port 402 anda distal portion 421 with an expandable member 406. The proximal anddistal skirts of expandable member 406 may be attached to exteriorsurface of catheter body 401. A Y-adapter having a port 402 may be influid communication with inflation lumen 407 that is defined by catheterbody 401, which extends from the proximal end of the catheter to a pointproximal to the catheter distal end, and which is in fluid communicationwith an inflatable interior of expandable member 406. Port 402 may beconfigured for attaching to an inflation fluid source or medium (notshown in FIG. 4). In one embodiment, port 402 may be a luer lock or aluer lock-type of fitting to couple to a syringe containing an inflationmedium. An infusion catheter 409 is disposed within elongated catheterbody 401, and may extend from proximal portion 420 and past expandablemember 406 near distal portion 421. Infusion catheter 409 forms a firstlumen 404 for delivering a therapeutic drug towards the distal end, andthe proximal end may include an infusion port 403 to couple with asyringe or other device containing anti-reperfusion injury drug. In oneembodiment, infusion port 403 may include a luer lock or a luerlock-type of coupling mechanism.

One significant difference between device 400 and device 300 is theconfiguration of guidewire 405 with respect to infusion catheter 409. Indevice 400, guidewire 405 does not extend throughout an entire length ofinfusion catheter 409. Instead, guidewire 405 extends externally alongan outer wall of elongated catheter from proximal portion 420 and enterselongated catheter body 401 near expandable member 406. A guidewirelumen 412 is formed within elongated catheter body 401 near the distalportion 421 to receive guidewire 405, and guidewire 405 also extendstowards a guide member 411 that is coupled near the distal tip ofinfusion catheter 409. Device 400 may be referred to as a “rapidexchange” (“RX”) catheter device because guidewire 405 is not insertedfrom a proximal portion of elongated catheter body 401 and threadedthroughout its entire length towards distal portion 421.

FIGS. 4B-4F illustrate various cross-sectional views of medical device400. For example, FIG. 4B shows a cross-sectional view taken along lineA-A near proximal portion 420 which includes infusion catheter 409forming first lumen 404 for passing an anti-reperfusion injury drugalong the elongated catheter body 401. FIG. 4C shows a cross-sectionalview taken along line B-B of elongated catheter body 401. Inflationlumen 407 is formed extending from port 402 and second lumen 410 isformed to receive infusion catheter 409. FIG. 4D shows a cross-sectionalview of device 400 taken along line C-C which includes one additionallumen formed by elongated catheter body 401. Inflation lumen 407 isformed within one section of elongated catheter body 401 whicheventually lead to expandable member 406. Second lumen 410 is alsoformed by elongated catheter body 401 to receive infusion catheter 409.As described above, infusion catheter 409 includes infusion lumen 404.This portion of device 400 also includes guidewire lumen 412 to receiveguidewire 405. FIG. 4E shows a cross-sectional view of device 400 takenalong line D-D (through expandable member 406) showing inflation lumen407 formed by expandable member 406, as well as infusion catheter 409forming infusion lumen 404. This section also includes guidewire 405disposed within guidewire lumen 412. Lastly, FIG. 4F is across-sectional view of device 400 taken along line E-E (near distalportion 421) of infusion catheter 409 coupled to guide 411 whichsupports guidewire 405. It should be noted that FIGS. 3A-3E and FIGS.4A-4F illustrate an embodiment of the catheter shaft that may be formedby a multi-lumen extrusion process (i.e., formed by extruding a singletube with multiple lumens defined by the tube wall). In an alternativeembodiment, the multiple lumens may be defined by separate coaxial orside-by-side tubular members.

The effective administration of the anti-reperfusion injury drug maydepend on an environment that is free from blood flow (i.e., blood flowmay “wash” the drug further downstream than intended, preventingabsorption into the arterial wall). The sequence of events illustratedin FIGS. 5A-5F and the block diagram 600 of FIG. 6, taken together, showone detailed embodiment of a method to prevent reperfusion injury usingmedical device 300 described above with respect to FIGS. 3A-3E. Thereperfusion procedure, in one embodiment, is a procedure prior to adirect treatment of a lesion with a balloon or stent (e.g., angioplastyor stent delivery to the lesion). FIG. 5A illustrates a cross-sectional,side view of arterial vessel 500 containing a lesion 503 causingblockage of blood flow 504 from a region proximal 501 to lesion 503 to aregion distal 502 to lesion 503. As described in greater detail above,the region distal 502 to lesion 503 is generally represented as theischemic region 506 of arterial vessel 500. Device 300 is advancedwithin arterial lumen 500 to a position proximal 501 to lesion 503. Inone embodiment, guidewire 305 may first be percutaneously introducedinto the cardiovascular system of a patient through the brachial orfemoral arteries and advanced through the vasculature until the distalend of the guidewire 305 is positioned near the region proximal 501 tolesion 503.

Elongated catheter body 301, including expandable member 306 andinfusion catheter 309 is tracked over guidewire 305 and also positionednear the region proximal 501 to lesion 503. Expandable member 306 ofdevice 300 is inflated, as shown in FIG. 5A, in order to occlude bloodflow 504 in the region proximal 501 to lesion 503, block 601. As shownin FIG. 5B, guidewire 305 is advanced in a distal direction past lesion503 to the region distal 502 of lesion 503 by threading through lumen304 of infusion catheter 309, block 602. In one embodiment, infusioncatheter 309 of device 300 may also be advanced to the region distal 502to lesion 503, block 603. Infusion catheter 309 is slideable within alumen 310 formed within elongated catheter body 301.

Next, as illustrated in FIG. 5C, an anti-reperfusion injury drug 512 isreleased from infusion catheter 309 into the region distal 502 to lesion503. In one embodiment, anti-reperfusion injury drug 512 is releasedfrom lumen 304 formed by infusion catheter 309. Anti-reperfusion injurydrug 512 is allowed to infuse to ischemic region 506 of arterial vessel500, block 604. After a period of time as determined by the physician ordevice operator, infusion catheter 309 is removed from distal region 502and withdrawn from arterial lumen 500 while guidewire 305 remains distalto lesion 503, block 605. As illustrated in FIG. 5D, expandable member306 is deflated to allow for the removal of device 300 from arteriallumen 500. In one embodiment, occlusion of blood flow by expandablemember 306 may be allowed to continue for a specified period of timeeven after the delivery of anti-reperfusion injury drug 512. This allowsfor the drug to infuse sufficiently into the arterial wall near ischemicregion 506 for maximum effectiveness.

After the delivery of anti-reperfusion injury drug 512, a dilating orreperfusion device may be applied to lesion 503, block 606. Asillustrated in FIG. 5E, a separate catheter device 350, having anexpandable stent 351 disposed near a distal end is advanced overguidewire 305 through arterial lumen 500 and positioned near lesion 503.Prior to deployment, stent 351 of device 350 is shown in a contractedstate positioned near lesion 503. Stent 351 may then be deployed fromdevice 350 and allowed to expand (either through balloon expansion orself expansion) to clear the blockage caused by lesion 503, andre-establish blood flow from the region proximal 501 to lesion 503 tothe region distal 502. For a self-expanding stent, a sheath may beinitially disposed over the stent to maintain it in a contracted state(e.g., as shown in FIG. 5E). The sheath (not shown) may then be removedto allow the stent to self-expand. The normal blood flow from the regionproximal 501 is generally represented by arrows 504 and the normal bloodflow in the region distal 502 to lesion 503 is generally represented byarrows 505 (e.g. as shown in FIG. 5F). As such, the treatment of anischemic region with an anti-reperfusion injury drug prior toestablishing blood flow prevents the occurrence of reperfusion injury.

In an alternative method, expandable member 306 may be used for thereperfusion procedure. That is, instead of substituting device 350 afterthe removal of device 300, expandable member 306 of device 300 may beadvanced distally toward lesion 503 and inflated. This alternativeavoids the need for a second catheter device to perform the reperfusionprocedure, allowing for a reduction in treatment time and cost. Inanother embodiment, a double-balloon catheter (not shown) may be used toprovide a combination of drug delivery and dilation treatment. Forexample, the catheter may include a first proximal balloon and a seconddistal balloon. The double balloon catheter is disposed near a lesion sothat the first proximal balloon is proximal to the lesion and the seconddistal balloon is near the lesion. The first proximal balloon may firstbe inflated to occlude blood flow proximal to the lesion. An infusioncatheter or guidewire disposed within the catheter may be advanceddistal to the lesion and an anti-reperfusion drug released. After aperiod of time for the drug to take effect, the second distal balloonmay be inflated to treat the lesion, and subsequently deflated toreperfuse blood flow past the lesion.

In another embodiment, anti-reperfusion injury drug 512 may be deliveredwithout advancing infusion catheter 309 past lesion 503. For example,guidewire 305 is advanced past lesion 503 toward ischemic region 506(e.g., as illustrated in FIG. 5D). If lesion 503 were larger than shown,guidewire 305 may generate a hole through lesion 503, but not largeenough to cause significant blood flow from the proximal side. As such,an expandable member would not be required to occlude blood flowproximal to lesion 503. The anti-reperfusion injury drug 512 would thenbe released from a lumen defined by guidewire 305.

In one embodiment, on-time, in-situ recovery of vascular/microvascularflow may be assessed as part of the anti-reperfusion injury therapy. Theparameters that may be used for this assessment include blood pressure,flow velocity, flow volume, vascular resistance, vascular conductance,oxygen content in arterial and/or venous blood, the difference ofarterial and venous oxygen content, and a combination of theseparameters. In addition to flow reserve, biochemical markers, forexample inflammatory response markers such as II-1b, and white bloodcell content and activity markers such as myeloperoxidase activity andLDH can be used to assess the degree of reperfusion injury, if any.

FIGS. 7A-7C illustrate another treatment sequence for the delivery of ananti-reperfusion injury drug to an ischemic region of an arterialvessel, in which device 400 described above with respect to FIGS. 4A-4Fis used. FIG. 7A illustrates device 400 advanced within arterial lumen500 to a position proximal 501 to lesion 503. Blood flow towards lesion503 has been occluded by the inflation of expandable member 406 tooccupy a substantial portion of the diameter of arterial vessel 500. Inone embodiment, expandable member 406 may be an inflatable balloon.Device 400 reflects a “rapid exchange” configuration for guidewire 405in which only a distal portion of device 400 tracks over guidewire 405,instead of guidewire 405 advanced through an entire length of elongatedcatheter body 401. Guidewire 405 is inserted within elongated catheter401 through expandable member 406 and anchored to infusion catheter 409with guide 411. Once blood flow has been occluded by expandable member406, guidewire 405 is advanced past lesion 403 to distal region 502(i.e., near ischemic region 506).

Next, as illustrated in FIG. 7B, infusion catheter 409 is advanced pastlesion 503 along guidewire 405 to distal region 502. Once in position,the anti-reperfusion injury drug 512 is released from the distal tip ofinfusion catheter 409 for absorption by the arterial wall of ischemicregion 506. After delivery of anti-reperfusion injury drug 512, infusioncatheter 409 is retracted back across lesion 503, followed by guidewire405. Expandable member 406 is deflated and device 400 may then beremoved from arterial lumen 500, as illustrated in FIG. 7C. A dilationcatheter (e.g., a balloon catheter or stent catheter 350 shown in FIG.5E) may be advanced over guidewire 405 to lesion 503 for treatment, andsubsequent re-establishment of blood flow towards distal region 502 ofarterial vessel 500.

In an alternative embodiment, it may not be necessary for the drugdelivery device to include an infusion catheter to release the drug inthe region distal to the lesion. FIGS. 8A-8C illustrate another sequenceof events related to an alternative method for the delivery of ananti-reperfusion injury drug in which the guidewire may be used torelease the anti-reperfusion injury drug. Catheter device 800 includes adistal portion with an expandable member 806 to occlude blood flow in aregion proximal 501 to lesion 503, as shown in FIG. 8A. A guidewirelumen 809 is formed within elongated catheter body 801 for theadvancement of guidewire 805 past lesion 503 and towards the regiondistal 502 to lesion 503 (and near ischemic region 506). In oneembodiment, the structure of guidewire 805 may form a lumen for passingthe drug from an injection port near the proximal end of device 800 forrelease from the distal tip. As shown in FIG. 8B, anti-reperfusioninjury drug 512 is released from guidewire 805 for absorption by thearterial wall of ischemic region 506. Expandable member 806 may then bedeflated, and device 800 removed from arterial lumen 500, as shown inFIG. 8C.

As described above, embodiments of medical devices described herein havebeen generally described as being adapted for the delivery ofanti-reperfusion injury drugs to an arterial vessel. Theanti-reperfusion injury drug may be one or a combination of thefollowing antibodies, peptides, biochemical compounds, small molecules,antisense agents that interfere specific RNA transcription, and/ordecoys that interfere VCAM. The peptides may include IGF-I, GrowthHormone, BNP, estrogen, VEGF, FGF, and/or HGF. Biochemical compounds mayinclude adenosine, adenosine, adenosine isoforms, Na/H exchangeinhibitors, Na/K exchangers, NO donors, calcium channel blockers,calcium antagonists, anti-oxidants, and/or super-oxide scavengers. Smallmolecules may include those composed with active sites of theabove-mentioned drugs. The antisenses and decoys may include thoseinhibiting the pathway involved in reperfusion signaling or preventingcell survival. The anti-reperfusion injury drugs listed may beformulated such that they are suitable for local therapy, for example,with respect to a guidewire or infusion catheter based delivery system.In one embodiment, the drug concentration may be higher relative tosystemic intravenous administration.

In the foregoing specification, a medical device has been described withreference to specific exemplary embodiments thereof. For example, themedical device may be used occlusive lesions formed near the walls of anarterial vessel. It will, however, be evident that various modificationsand changes may be made thereto without departing from the broaderspirit and scope of the medical device as set forth in the appendedclaims. The specification and figures are, accordingly, to be regardedin an illustrative rather than a restrictive sense.

What is claimed is:
 1. A method to prevent reperfusion injury, themethod comprising: advancing a guidewire through a lesion and near anischemic region distal to the lesion; advancing an occlusion catheterproximal to the lesion; occluding blood flow proximal to the lesioncausing blockage of blood flow to the ischemic region distal to thelesion, wherein occluding comprises occluding blood flow proximal to thelesion, but not across the lesion or distal to the lesion; thendelivering a therapeutic drug to the ischemic region distal to thelesion using a lumen in the guidewire; and treating the lesion with adilating device to reintroduce blood flow to the ischemic region distalto the lesion, wherein the therapeutic drug is delivered before treatingthe lesion with the dilating device.
 2. The method of claim 1, whereindelivering comprises releasing anti-reperfusion injury drug from aninfusion lumen of the guidewire proximal to the ischemic region and forabsorption by the arterial wall of the ischemic region.
 3. The method ofclaim 1, wherein the occlusion catheter: includes a guidewire lumenformed within an elongated catheter body for the advancement of theguidewire past the lesion and towards the ischemic region distal tolesion; does not include an infusion catheter to release the drug in theregion distal to the lesion.
 4. The method of claim 1, wherein advancingfurther comprises: progressing the guidewire disposed within theinfusion catheter past the lesion to the region distal to the lesion;and tracking the occlusion catheter over the guidewire to the regiondistal to the lesion.
 5. The method of claim 1, wherein the guidewiredoes not increase a blood flow across the lesion.
 6. The method of claim1 wherein delivering a therapeutic drug comprises deploying ananti-reperfusion injury agent to the region distal to the lesion; andwherein treating the lesion with a dilating device comprises expanding astent to the lesion after deploying the anti-reperfusion injury agent.7. The method of claim 1 wherein advancing the guidewire furthercomprises advancing a guidewire having a diameter small enough toadvance through the lesion without causing a large channel or areperfusion pathway to form through the lesion.
 8. The method of claim 1wherein occluding blood flow comprises inflating a balloon proximal tothe lesion to cause the blockage; and wherein treating the lesion with adilating device comprises deflating the balloon, advancing the balloonto the lesion, and reinflating the balloon to treat the lesion.
 9. Themethod of claim 1, wherein the dilating device is coupled to theocclusion catheter.
 10. The method of claim 1, wherein treating furthercomprises one of inflating a dilatation balloon to expand the lesion,inflating the expandable member to the lesion to reintroduce blood flowto the distal region, and expanding a stent to the lesion.
 11. Themethod of claim 1 wherein delivering the therapeutic drug comprisesapplying an anti-reperfusion injury drug to the region distal to thelesion for a period of time sufficient to allow the drug to infuse intoan arterial wall and take effect, prior to treating the lesion with adilating device.
 12. A method to prevent reperfusion injury, the methodcomprising: advancing a guidewire having an infusion lumen within anarterial vessel from a region proximal to a lesion to an ischemic regiondistal to the lesion; delivering an anti-reperfusion injury drug fromthe infusion lumen to the ischemic region distal to the lesion, wherein,during delivering, only an outer surface of the guidewire is exposedthrough the lesion, and the exposed outer surface has a diameter smallenough to advance through the lesion, and wherein blood flow is onlyoccluded proximal to the lesion, but is not occluded across the lesion,and is not occluded distal to the lesion; and treating the lesion with adilating device coupled to the infusion lumen to reintroduce blood flowto the ischemic region distal to the lesion, wherein theanti-reperfusion injury drug is delivered before treating the lesionwith the dilating device.
 13. The method of claim 12, wherein advancingfurther comprises occluding a blood flow from a region proximal to thelesion prior to delivering the anti-reperfusion drug to maintainblockage of blood flow in the region proximal to the lesion.
 14. Themethod of claim 12, wherein treating further comprises one of inflatinga dilatation balloon to the lesion, expanding a stent to the lesion, andassessing any injury to the arterial vessel by the reintroduction ofblood flow to the region distal to the lesion.
 15. The method of claim12, wherein during delivering, only an outer surface of the guidewire isexposed through the lesion, and the exposed outer surface has a diametersmall enough to advance through the lesion without causing a largechannel or reperfusion pathway to form through the lesion.